"""到期结算回填：从本地指数或 OKX 历史指数锚定 settle_index_px。"""

from __future__ import annotations

import logging
import time
from typing import Any

from apps.collector.okx_rest import OkxRestClient, safe_float
from packages.db.repository import Repository
from packages.domain.expiry import expiry_ms_from_ymd

log = logging.getLogger("worker.settle")

# 本地 index_ticks 与到期时刻的最大偏离
_LOCAL_MAX_DELTA_MS = 15 * 60 * 1000


def list_expiry_ymds_needing_settle(repo: Repository, *, now_ms: int | None = None) -> list[str]:
    """option_quotes 中已到期且尚未写入 settlements 的 expiry_ymd。"""
    now = int(now_ms if now_ms is not None else time.time() * 1000)
    rows = repo.conn.execute(
        """
        SELECT DISTINCT expiry_ymd FROM option_quotes
        WHERE expiry_ymd IS NOT NULL AND expiry_ymd != ''
        ORDER BY expiry_ymd ASC
        """
    ).fetchall()
    out: list[str] = []
    for r in rows:
        ymd = str(r["expiry_ymd"])
        try:
            settle_ts = expiry_ms_from_ymd(ymd)
        except ValueError:
            continue
        if settle_ts > now:
            continue
        if repo.get_settlement(ymd) is not None:
            continue
        out.append(ymd)
    return out


def resolve_settle_index(
    repo: Repository,
    *,
    expiry_ymd: str,
    underlying: str,
    index_inst_id: str,
    exchange: str = "okx",
    client: OkxRestClient | None = None,
) -> dict[str, Any] | None:
    """
    解析到期指数。优先本地 index_ticks 最近点；否则 OKX 历史指数 K 线。
    """
    settle_ts = expiry_ms_from_ymd(expiry_ymd)
    local = repo.nearest_index_tick(
        underlying=underlying,
        target_ts_ms=settle_ts,
        max_delta_ms=_LOCAL_MAX_DELTA_MS,
    )
    if local is not None:
        return {
            "expiry_ymd": expiry_ymd,
            "settle_ts_ms": settle_ts,
            "settle_index_px": float(local["index_px"]),
            "exchange": exchange,
            "underlying": underlying,
            "source": "index_ticks",
            "source_ts_ms": int(local["ts_ms"]),
        }

    own_client = client is None
    cli = client or OkxRestClient()
    try:
        px, src_ts = cli.fetch_index_at(index_inst_id, settle_ts)
        if px is None:
            return None
        return {
            "expiry_ymd": expiry_ymd,
            "settle_ts_ms": settle_ts,
            "settle_index_px": float(px),
            "exchange": exchange,
            "underlying": underlying,
            "source": "okx_history_index",
            "source_ts_ms": src_ts,
        }
    finally:
        if own_client:
            cli.close()


def backfill_settlements(
    repo: Repository,
    *,
    underlying: str,
    index_inst_id: str,
    client: OkxRestClient | None = None,
    ymds: list[str] | None = None,
    now_ms: int | None = None,
) -> dict[str, Any]:
    """回填到期锚点；返回 {filled, skipped, pending, errors}。"""
    targets = ymds if ymds is not None else list_expiry_ymds_needing_settle(repo, now_ms=now_ms)
    filled: list[str] = []
    skipped: list[str] = []
    errors: list[str] = []

    own_client = client is None
    cli = client
    try:
        for ymd in targets:
            if repo.get_settlement(ymd) is not None:
                skipped.append(ymd)
                continue
            try:
                if cli is None:
                    cli = OkxRestClient()
                row = resolve_settle_index(
                    repo,
                    expiry_ymd=ymd,
                    underlying=underlying,
                    index_inst_id=index_inst_id,
                    client=cli,
                )
                if row is None:
                    errors.append(f"{ymd}: settle index unavailable")
                    continue
                repo.upsert_settlement(
                    expiry_ymd=row["expiry_ymd"],
                    settle_ts_ms=int(row["settle_ts_ms"]),
                    settle_index_px=float(row["settle_index_px"]),
                    exchange=str(row["exchange"]),
                    underlying=str(row["underlying"]),
                )
                filled.append(ymd)
                log.info(
                    "settled %s index=%.4f source=%s",
                    ymd,
                    row["settle_index_px"],
                    row.get("source"),
                )
            except Exception as e:  # noqa: BLE001
                errors.append(f"{ymd}: {e}")
                log.exception("backfill %s failed", ymd)
    finally:
        if own_client and cli is not None:
            cli.close()

    return {"filled": filled, "skipped": skipped, "errors": errors, "targets": targets}


def ensure_settlements_for_ymds(
    repo: Repository,
    ymds: list[str],
    *,
    underlying: str,
    index_inst_id: str,
    client: OkxRestClient | None = None,
    now_ms: int | None = None,
) -> dict[str, Any]:
    """对给定到期日尽量回填（未到期的跳过）。"""
    now = int(now_ms if now_ms is not None else time.time() * 1000)
    due = []
    for ymd in sorted(set(ymds)):
        try:
            if expiry_ms_from_ymd(ymd) <= now:
                due.append(ymd)
        except ValueError:
            continue
    return backfill_settlements(
        repo,
        underlying=underlying,
        index_inst_id=index_inst_id,
        client=client,
        ymds=due,
        now_ms=now,
    )


# re-export for typing clarity
__all__ = [
    "backfill_settlements",
    "ensure_settlements_for_ymds",
    "list_expiry_ymds_needing_settle",
    "resolve_settle_index",
    "safe_float",
]